﻿using System;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading;
using System.Runtime.Serialization.Formatters.Binary;
using System.IO;
using System.Text.RegularExpressions;
using System.Collections.Generic;

namespace displaycongress_desktop
{
    // State object for reading client data asynchronously

    public class StateObject
    {
        // Client  socket.
        public Socket workSocket = null;
        // Size of receive buffer.
        public const int BufferSize = 1024;
        // Receive buffer.
        public byte[] buffer = new byte[BufferSize];
        // Received data string.
        public StringBuilder sb = new StringBuilder();
    }

    public class AsynchronousSocketListener
    {
        private static byte[] bytesReceived = new byte[0];

        // Thread signal.
        public static ManualResetEvent allDone = new ManualResetEvent(false);

        private Socket listener;
        private bool keepRunning = true;

        public AsynchronousSocketListener()
        {
            getIp();
        }

        public void StartListening()
        {
            // Data buffer for incoming data.
            byte[] bytes = new Byte[1024];

            // Establish the local endpoint for the socket.
            // The DNS name of the computer
            // running the listener is "host.contoso.com".
            IPHostEntry ipHostInfo = Dns.Resolve(Dns.GetHostName());
            IPAddress ipAddress = ipHostInfo.AddressList[0];
            IPEndPoint localEndPoint = new IPEndPoint(ipAddress, 11000);

            // Create a TCP/IP socket.
            listener = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
            listener.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, true);

            keepRunning = true;

            // Bind the socket to the local endpoint and listen for incoming connections.
            try
            {
                listener.Bind(localEndPoint);
                listener.Listen(100);

                while (keepRunning)
                {
                    // Set the event to nonsignaled state.
                    allDone.Reset();

                    // Start an asynchronous socket to listen for connections.
                    Console.WriteLine("Waiting for a connection...");
                    listener.BeginAccept(
                        new AsyncCallback(AcceptCallback),
                        listener);

                    // Wait until a connection is made before continuing.
                    allDone.WaitOne();
                }

            }
            catch (Exception e)
            {
                Console.WriteLine(e.ToString());
            }

            Console.WriteLine("\nPress ENTER to continue...");
            Console.Read();

        }

        public void StopListening()
        {
            listener.Shutdown(SocketShutdown.Both);
            keepRunning = false;
            //listener.Disconnect(true);
            listener.Close();
        }

        public static void getIp()
        {
            string strHostName;
            strHostName = Dns.GetHostName();
            Dns.GetHostEntry(strHostName);
            Console.WriteLine("Local Machine's Host Name: " + Dns.GetHostEntry(strHostName));
        }

        public static void AcceptCallback(IAsyncResult ar)
        {
            // Signal the main thread to continue.
            allDone.Set();

            // Get the socket that handles the client request.
            Socket listener = (Socket)ar.AsyncState;
            Socket handler = listener.EndAccept(ar);

            Console.WriteLine("hoi, begin Receive?");

            WaitForData(handler);
        }

        public static void WaitForData(Socket handler)
        {
            // Create the state object.
            StateObject state = new StateObject();
            state.workSocket = handler;
            handler.BeginReceive(state.buffer, 0, StateObject.BufferSize, SocketFlags.None, new AsyncCallback(ReadCallback), state);

            Console.WriteLine("End receive?");
        }

        public static void ReadCallback(IAsyncResult ar)
        {
            //Console.WriteLine("begin readCallback");

            String content = String.Empty;

            // Retrieve the state object and the handler socket
            // from the asynchronous state object.
            StateObject state = (StateObject)ar.AsyncState;
            Socket handler = state.workSocket;

            //Console.WriteLine(ar.ToString());

            // Read data from the client socket. 
            int bytesRead = handler.EndReceive(ar);

            //Console.WriteLine(bytesRead);

            if (bytesRead > 0)
            {
                //Console.WriteLine(bytesRead);
                byte[] temp = new byte[bytesReceived.Length];
                for (int i = 0; i < bytesReceived.Length; i++)
                {
                    temp[i] = bytesReceived[i];
                }

                bytesReceived = new byte[temp.Length + bytesRead];

                for (int i = 0; i < temp.Length; i++)
                {
                    bytesReceived[i] = temp[i];
                }

                for (int i = 0; i < bytesRead; i++)
                {
                    bytesReceived[temp.Length + i] = state.buffer[i];
                }

                // There  might be more data, so store the data received so far.
                if (Encoding.ASCII.GetString(state.buffer).IndexOf("<EOF>") != -1)
                {
                    // All the data has been read from the 
                    // client. Display it on the console.
                    content = Encoding.ASCII.GetString(bytesReceived, 0, bytesReceived.Length).Substring(0, bytesReceived.Length - 5);
                    
                    //Console.WriteLine("Read {0} bytes from socket. \n Data : {1} | {2}", bytesRead, content.ToString(), Encoding.ASCII.GetString(state.buffer));

                    Engine.sDecoder.decode(content.ToString(), handler);

                    bytesReceived = new byte[0];

                    WaitForData(handler);
                }
                else
                {
                    // Not all data received. Get more.
                    //Console.WriteLine(Encoding.ASCII.GetString(state.buffer));
                    WaitForData(handler);
                }
            }
        }

        public static void Send(Socket handler, String data)
        {
            // Convert the string data to byte data using ASCII encoding.
            byte[] byteData = Encoding.ASCII.GetBytes(data);

            if (!handler.Connected)
            {
                Console.WriteLine("Not connected");
            }

            // Begin sending the data to the remote device.
            //handler.Send(byteData, byteData.Length, SocketFlags.None);
            handler.BeginSend(byteData, 0, byteData.Length, SocketFlags.None, new AsyncCallback(SendCallback), handler);
        }

        private static void SendCallback(IAsyncResult ar)
        {
            try
            {
                // Retrieve the socket from the state object.
                Socket handler = (Socket)ar.AsyncState;

                // Complete sending the data to the remote device.
                int bytesSent = handler.EndSend(ar);
                //Console.WriteLine("Sent {0} bytes to client.", bytesSent);

                //handler.Shutdown(SocketShutdown.Both);
                //handler.Close();
                //handler.Disconnect(true);

                //AsynchronousSocketListener listener = new AsynchronousSocketListener();
                //listener.StartListening();
            }
            catch (Exception e)
            {
                Console.WriteLine(e.ToString());
            }
        }
    }
}